There is indirect evidences that the effectiveness of the sympathetic nervous system is diminisheing with age. The number of sympathetic nervous endings is decreasing with age and therefore the overall reaction of the cardiovascular system has a different character in old as compared with young individuals. No attention has been given to the subtle influence of the sympathetic nervous system on the nutritional state of the arterial wall. It is the objective of this research project to study the effect of the long term sympathectomy on the arterial wall. The study includes such parameters as changes of the arterial wall mechanical properties and specific aspects of biochemistry and histology. It is expected that compensation of the missing sympathetic nervous innervation leads to metabolic derangement in the vessel wall and predisposes the vessel to degenerative changes. If the proposed concept proves to be valid, attention will be given to a neglected aspect of the arterial wall pathology and possibly opening new avenues of treatment and prevention of degenerative vascular disease. BIBLIOGRAPHIC REFERENCES: Fronek, K., Intaglietta, M., Schmid-Schoenbein, G., Sundquist, M. and Fung, Y.C.: Non-contact method for three-dimensional analysis of vascular reactivity in-vivo and in-vitro. Federation of American Societies for Exp. Biology, Atlantic City, April 1975.